Pursuing Sustainability and Clean Energy at Earth Tools Inc.
Earth Tools’ main office, warehouses, and service center are located in rural Owen County. With about 15 employees, Earth Tools provides sales and service for two-wheel tractors, implements, and hand tools, retailed to small farmers and gardeners throughout North America. Earth Tools has been committed to environmental sustainability since it was founded more than 20 years ago and its Sustainable Systems Program has helped make ongoing improvements to the operations’ environmental footprint. Some key sustainability features at Earth Tools:Approaching net-zero electricity with 23 KW solar PV
Earth Tools has a 12 KW solar PV array on the roof of its main office and warehouse, installed in 2011 by Avery & Sun. In 2016, Earth Tools added an 11 KW ground-mount array, which provides a picnic pavilion and shades Warehouse #3. The combined 23 KW of solar PV enabled Earth Tools to generate more than 100% of its annual electricity needs in 2016. However, a shift from propane heat to high-efficiency heat pumps, along with business expansion, have increased electricity consumption and reduced the company’s “solar fraction” to 82%. The company has plans to expand its solar array in 2020 to return to net-zero electricity.
Energy Efficiency and Conservation
Following a comprehensive energy audit in 2014, which included a blower door test to identify sources of air infiltration, Earth Tools implemented numerous measures to conserve energy. These included:- Increasing attic insulation to R-60 above the office.
- Air sealing around the floor and ceiling perimeter using caulk and spray foam.
- Replacing propane space heaters and window air conditioners with high-efficiency mini-split heat pumps. By replacing propane space heaters with heat pumps our electricity usage has increased, but we’re able to supply the electrical demand with solar energy.
- The Metal Fabrication Shop was built using Structural Insulation Panels (SIPs), which provide a high insulation value and minimize air infiltration. The building is heated and cooled using mini-split heat pumps.
Water and Resource Conservation
A rainwater harvesting system supplies the water needs for the facility, with a 1,000 gallon tank on the second floor of the office supplying water to the restroom below. The restroom uses a composting toilet, which greatly reduces the need for water. The main office and warehouse were built using pole-barn construction techniques. Passive solar design supports the office’s heating needs. Salvaged barn wood was used extensively throughout the building. Earth Tools continually seeks to re-use materials and has systems to recycle all waste which can be recycled.